Machine tool



E. W. BAKE R Feb.- 18,' 1941.

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Patented Feb. 18, 1941 l UNITED STATESY PATENT OFFICE MACHINE TOOLEdward W. Baker, Lexington, Mass., assigner to Jeerson Union Company,Lexington, Mass., a corporation of Massachusetts Application March 30,193s, serial No. 199,040 2 Claims. (Cl. 279-2) The present inventionrelates to machine tools of arm34 against the adjacentedge of flange 26.and has as an object to provide apparatus where- The abutment edge offlange 26 is provided with by a predetermined sequence of operations mayone or more bores 35 receiving a compression be automatically enforced.spring or Springs 35 acting 0n the arm 34 to In the apparatus shown byway of example in swing member 3I in a counterclockwise direction. 5 theaccompanying drawings, means are provided As will be hereinafterdescribed, means is profor determining the sequence of operation of avided for positively swinging the members 3I plurality of tools such asa roughing tool and a about their pivots ina manner to cause the axiallyiinishing tool designed to act successively on a extending arms 33 to bemoved apart to a limit workpiece. The illustrated apparatus alsonposition determined by abutment of arms 34 10 cludes a collapsible workholder and means for with the cooperating edges of flange 26.y Withcontrolling the work holder in correlation With arms 33 in their limitpositions apart, their exthe control of the tools. The invention alsointernal end portions 31 are disposed as segments cludes the work holderper se. of a cylinder and are provided with threads for In the drawings,engagement with the linternal threads of a Work- 1 5y Figure 1 is anaxial section of the apparatus. piece 33. The threaded portions 31 ofarms 3i Figure 2 is an elevation of the work holder. arey backed byabutment shoulders 39 which limit Figure 3 is a section substantially online 3-3 the extent of insertion of the threaded portions of Figure 1,and in the workpiece. The latter is herein assumed Fig. 3a. is adiagrammatic representation of to be of generally the form of theworkpiece 20 camAgrooves which determine the movements of shown in mycopending application Serial No. the roughing and iinishing tools.199,039,` le'd March 30, 1938.

Referring to the drawings, reference numeral In thev operation of thedevice, the spindle I5, I0 designates generally aframehaving pedestalsas seen from its right hand end, is rotated in a Y. II and I2 which havebores horizontally aligned counterclockwise direction, and, assumingthat 25 and'receiving bushings I3 and I4. Journaled in arms 33, whichconstitute a segmental arbor, are the bushings is a spindle I5 whichatone end has at' their limit positions apart, the workpiece 38 a headI6, the spindle having an axial through is moved by the attendant towardthe arbor in bore I'I. Head I6 comprisesv an externally coaxial relationtherewith and the arbor threads threaded extr'eniityv backedI by aradial flange I8 itself intothe workpiece until the inner edge of 30whichis inthrust relation with the adjacent en'd the latter abuts theshoulders 39 whereupon the of bushingv I4. At its other end, spindle I5has/'a workpieceVv participates in the rotation of the threadedvportionI9, a reduced cylindrical por'- spindle. When the expanding force isreleased tion 20- and a reduced and threaded extremity 2I. from armportions 33, they are moved inwardly i A nut 22- is threaded on portionI9 and is in due to the action of springs 36, the extent of 35 thrustrelation with the adjacent end of bushing inward movement being suchthat the threads of I3. A pulley 23, here shown as being stepped, isthearbor are entirely released from the threads fixedon the spindlebetween pedestals II and I2. of the workpiece so thaty the latter may bere- A work holder generally designated at 24 commoved. I prises abody 25in the form of a cap with an It will be understood from the above thatin 40,

internally threaded cylindrical flange 26 threaded the preferredembodiment as illustrated, no outon the extremity of head I6 and inabutment ward radial pressure is exerted on the workpiece with flangeI8. The cap comprises a cover porfor the purpose of locking it to thearbor. On tion 21 which has an axial opening 28 formed the contrary, thefully expanded arbor has an at the intersection of three radial slots29, the easy threading t with the workpiece so as to 45.

slots-being equi-distantly spaced. Furthermore, thread into the latteras the same is manually portion 2-1 is provided with-three bores 30which held, the workpiece being caused to rotate with intersect theslots 29, respectively, at right angles the arbor only when furtherrelative axial movethereto. ment becomes impossible due to the abutmentPositioned in each slo-t 29 is a bell crank memof the workpiece Withshoulders 39. 5G ber 3| which is pivoted on a pin 32 positioned in Thebore II of the spindle I5 has disposed theintersecting bore 30, Figurel.Each member therein a pair of bushings 4D and 4I which slid- 3l has agenerally vaxially -extending arm 33 and ably receive a rod 42 ofcircular cross-section. a generally vradially extending arm 34.Clockwise At its right hand end, Figure 1, rod 42 has pivswingingof themember 3| is limited by abutment oted-to itsextremity, through a loosetongue and 55 groove joint, a conical wedge member 43 for cooperationwith the generally correspondingly inclined inner edges, as at 44, ofthe arbor segments. At its other end, rod 42 projects somewhat beyondthe extremity of the spindle and into a. cylinder 45 which has aninternally threaded neck 46 threaded on the spindle eX- tremity 2|. Theextremity of rod 42 within cylinder 45 has fixed thereon a piston 41which is urged to the left, Figure 1, by a compression spring 48. Thecylinder is provided with a vent 49 at the right hand side of the piston41, Figure l, and its end wall, on the same side of the piston, isprovided with `an annular recess in which is disposed a packing ring 58to provide a tight joint with rod 42.

The spindle bore |1 closely surrounds the rod 42 at the spindleextremity 2i|. 'I'he extremity 2| may be provided with diametrical boresreceiving a pin 5| which is passed through a slot 52 of rod 4-2. Rod 42is thus caused to rotate with spindle |5 and with cylinder 45 and theslot 52 is of suflicient length to afford the necessary range ofreciprocation for rod 42. The pin 5| and slot 52 may be omitted sincerod 42 will tend to rotate with the spindle, and, in any event, it isnot essential that the rod and spindle rotate together.

Cylinder 45 has threaded thereon a cover 53 which has an axial bore inwhich is swiveled the end -of .a tube 54 which leads from a controlvalve 55.

Frame I8 provides upright side wall portions 56 and 51, Figures 1 and 3,in which are journaled the ends of a shaft 58 which is horizontallydisposed and in a plane perpendicular to the axis of spindle |5. At oneend, shaft 58 has fixed thereto a boss 59 from which extends a radiallever 68. Boss 59 has a circular rib 6| which is coaxial with shaft 58and at one point, the rib has a recess 62 for cooperation with theextremity of the radially disposed stem 63 of valve 515.

Valve comprises a hollow body 64 which presents oppositely faced conicalseats 65 and 66 for alternate cooperation with valve members 61 and 68fixed on stem 63, valve 68 being secured to the lower extremity of thelaltter as by a screw 69. The upper portion of stem 63 is rectilinearlyguided in the tubular portion 10 of a spider which is removably engagedand centered in .the upper portion of the valve body 64. Tube 54 is ledinto the valve body cavity between valve members 61 and 6B. The bottomof the valve body is closed by a threaded plug H pierced to receive theend of a tube 12 leading from a suitable source of fluid under pressure,A compression spring 13 interposed bet-ween plug 1| and valve member 68normally urges valve stem 63 upwardly .and if the recess 62 is inregister with the extremity of the valve stem valve member 68 will beseated and valve member 61 unseated.

If, now, lever is swung in a clockwise direction toward the position ofFigure 1, the inclined wal-l of recess 62 will cam the valve stemdownwardly and valve member 61 will be seated and valve member 68unseated. The pressure fluid is thus given access to tube 54 and to lefthand en-d ofcylinder 4'5 so that piston 41 and rod 42 will move to theright hand position shown. The

wedge portion 43 has thus been caused to coact with the inner edges 44of the arbor segments and the latter have been forced apart and held intheir outer limit positions wherein the tting may be threaded thereon ashereinbefore described, equalized .action of the wedge portion beingassured due to its loose `pivotal connection with rod 42. When lever 6|)is swung back to a position determined by the abrupt wall of recess 62engaging the extremity of stem 63, valve member 68 will be seated byspring 1:3 and valve member 61 unseated. The supply of fluid underpressure is thus cut off from cylinder 4-5 and the piston is moved `tothe left under .the influence of spring 48, thus withdrawing wedgeportion 43 and permitting the arbor to be collapsed as the result of the-action of springs 36. Movement of the piston 41 under the action ofspring 48 is entirely free, since tube 54 is in communication past thevalve member 61 and the spider, which supports guide 613, with theatmosphere. It will be understood that the position of the arborsegments, Figure 1, obtains only when stem 63 rides on the circularportion of rib 6 I.

A ring 14 mounted on the reduced portion 20 of spindle |5 has aninternal central annular recess 1'5 and outwardly disposed annularrecesses in which aredisposed packing rings 1e6 and 11 which form atight t with the periphery of portion 20. Ring 14 is held againstrotation by means of a screw 18 threaded into the upper end of pedestaland engaged in a peripheral notch 19 in ring 14. Axial displacement ofring 1i4 is prevented by the shoulder on the spindle at the rig-ht ofthe reduced portion 20 and by the neck 46 of cylinder 4i5.`

Portion 20 has an aperture 80 formed therein in register with recess 15and bushings 40 and 4| have one or more axially extending throughopenings 48 and 4i|. Ring 14 has a radial bore running into recess 'I5and into which is connected a pipe 8| leading from a source of cleaningand/'or lubricating fluid.

In the operation yof the apparatus, fluid is preferably continuously fedthrough tube 8| into recess 15 and thence through passage 80, bore I1and passages 40 and 4| to the tool holder, the iiuid passing throughopening 28 and out between the arbor segments. A principal function ofthe described fluid supply is to keep the arbor segments clear offoreign matter, such as cuttings, which might otherwise accumulate andblock the free movement of the segments. The fluid may also serve tokeep-the parts lubricated.

Escape of the fluid from recess 15 is prevented, as far as possible, bythe packings 16 and 11, but any fluid escaping past packing 11 is keptfrom bushing |3 by the nut 22. The fluid is largely kept from cylinder45 by the packing 50 and any which passes this packing may escape fromthe cylinder through vent 48. This Vent also serves,A it will beunderstood, to eliminate dash-pot effects in the cylinder. Y

The upright side wall portions 56 and 51, hereinbefore referred to asproviding journals for the ends of shaft 58, support at their upper endspairs of parallel walled, undercut guideways 82 and 83 directly aboveand parallel to shaft 58. The inner ends Iof the pairs of ways areconnected by a downwardly projecting block 84 provided with a bore inwhich the intermediate portion of shaft 58 is journaled, the shafthaving collars 85 and 86 xed thereon at the ends of block 84andcooperating with the latter to prevent axial displacement of shaft 58.The shaft has fixed thereon, adjacent the walls 56 and 51, respectivelycylinders 81 and 88 which have formed therein the parallel-walled Ycamgrooves 92 on whose extremity is rotatable a roller 93 which ispositioned in groove 89. Slide 9| has on its top surface a groove whichextends parallel to the axis of spindle I and is engaged by a rib 94formed on the bottom of a tool holder block 95. The latter has end angesas at 98 provided with apertures elongated in the longitudinal directionof rib 94 and receiving cap screws 91 which are threaded into slide 9|.Block 95 is thus adjustable in the axial direction of the spindle I5.

Block 95 has formed therein a through opening 98 which is of rectangularcross-section and is perpendicular to the vertical plane of the axis ofspindle I5. A tool 99 is disposed in opening 98 and has an upper cuttingedge |00. The tool is rmly held in the block by the downwardly actingscrews IUI and the laterally acting screws |02.

A slide |03, reciprocable on ways 83, carries a roller |04 which isdisposed in cam groove 90. A tool holder block |05 is adjustable onslide |03 in the manner described with reference to block 95.

Block |05 has a through passage |06 which extends perpendicularly to theaxis of spindle I5, the passage being inwardly upwardly enlarged at |01to provide downwardly faced end abutment surfaces |08 and |09. A pair oyokes ||0 and III positioned within block |05 have threaded shanks I I2and I I3 passed upwardly through top openings in the block, the yokesreceiving a tool |I4 which has a lower cutting edge |I5. Nuts threadedon the upper portions of shanks |I2 and I |3 serve to draw the endportions of tool ||4 against abutment surfaces |08 and |09 while capscrews |I6 may be provided for exerting lateral seating pressure on thetool.

With the lever 60 in its initial or rest position, the rollers 93 and|04 are in the remote ends of grooves 89 and 90, Figures 3 and 3a. Afterthe workpiece has been applied to the arbor,` continued blockwisemovement of lever 60 rapidly advances the slides 9| and |03 toward theworkpiece which, it will be understood, is in the plane of the tools 99and II4. In the present instance,

' the workpiece has a circumferential rib 38a and a ball portion 38hwhich it is desired to machine, and, accordingly, edges |00 and |I5 areprovided with the required contour.

Tool 99 is a roughing tool and tool II4 a nishing tool and,consequently, the forrner is to be engaged with the workpiece prior tothe latter. As roller 93 approaches the innermost point 89 of groove 89,the workpiece is engaged by tool 99 and the roughing operation iscompleted as point 89 is reached. Roller 93 now passes into theoutwardly directed terminal portion 89 of groove 09 so that tool |00 isretracted and as this occurs, roller |04 approaches the innermost point90 of groove 90 so that the workpiece is engaged by tool II4. Theiinishing operation is completed when roller |04 reaches point 90' andas the roller passes into the outwardly directed terminal portion 90" ofgroove 90, the finishing tool is retracted. The clockwise movement oflever E0 has now reached its limit and this limit may be determined bythe abutment of roller |04 with the closed end of groove portion 90". Itwill be understood that throughout the swing of lever 60, valve stem 83has been riding on the circular portion of rib 6| so that the workpiecehas been securely held by the arbor.

As lever 60 is now swung in a counter-clockwise direction, tool I I4first moves in toward the work and then withdraws as roller |04 travelsto the outer end of groove 90. Tool 99 undergoes a similar movement andwhen lever 80 again comes to the position of Figure 1, the tools beingthen completely withdrawn, the arbor collapses so that the workpiece maybe removed by the attendant. In Figure 1, it is assumed that lever 60has just been returned to the illustrated position and the wedge rod isabout to move to the left.

From the above description, it will be seen that the operating trainsfor the tool holders and the operating train for controlling the wedgerod 42 all terminate in the common control lever 60 so that the entiresuccession of mechanical operations is carried out as the result ofmanipulation of the one lever. Efiicient and correct operation is thusassured.

It will be understood that various changes may be made in the form andarrangement of parts and that the disclosure herein is merelyillustrative. A possible modification contemplated is the provision ofcontinuous grooves as 89 and 90 so that shaft 58 may be rotated alwaysin the same direction, a cycle being completed, for example, during eachcomplete rotation of the shaft. The scope of the invention extends tothis as Well as to other modifications which may fall within thefollowing claims.

I claim:

1. Apparatus of the class described comprising a hollow spindle, a workholder secured to one end of said spindle, 'said work holder includingaxially extending jaws which are radially movable outwardly to engage ahollow work piece, a rod within said spindle and slidably guided formovement axially of the spindle, a wedge-shaped head pivoted to said rodand adapted to spread said jaws when urged therebetween, means limitingthe spread of the jaws, the pivotal connection between said rod and headassuring equalized action of the latter on said jaws, and means forreciprocating said rod.

2. In apparatus of the class described comprising a work holderincluding a body, a plurality of bell crank members pivoted to said bodyand swingable in radial planes, said bell crank members each comprisinga portion extending generally axially and a portion extending generallyradially with respect to said body, said axially extending portionsbeing externally threaded and constituting a segmental arbor forengagement with an internally threaded work piece, means for limitingthe extent of engagement of the work piece with the arbor, spring meanstending to collapse said arbor, and means for wedging the arbor segmentsapart, means for limiting spreading of said segments apart comprisingabutment portions on said body for cooperation with said radiallyextending portions of said bell crank members, said arbor being of theexact size to readily receive the work piece by rotation when the arborsegments lare in their limit positions apart.

EDWARD W. BAKER.

